278 



Subfamily PTYCHOPTERIN^. 



Latterly, this subfamily has beeu elevated by some authors to a 

 distinct family, as in the recently issued " Palsearctic Catalogue " 

 and in the " Catalogue of Diptera " by Kertesz, at present in 

 process of issue ; but to the writer it seems inseparable from the 



TlPULID^. 



The Ptychopteein^i: form a very compact group, differing in 

 two strong characters from the whole of the rest of the Tipclid.t. 

 These are the indistinctness of the transverse V-shaped suture on 

 the mesonotum, and the absence of the 6th longitudinal vein.* 



In Ptyclioptera itself there can be little doubt of the short 

 curved vein present being the 7th and not the 6th. In Blttaco- 

 morpha this vein is not so curved, but its position in the wing 

 and distance from the 5th makes it evident that this vein is also 

 the 7th. But in Idioplasta, Macrochile and Tanyderus t the general 

 position of the one vein present behind the 5th, its comparative 

 approximation to the 5th and its usually nearly straight course 

 makes it quite possible that in these three genera the vein present 

 may be the 6th, instead of the 7th. Thei-e seems nothing 

 illogical in the 6th being absent in one genus, and the 7th in an 

 allied genus, considering the great abnormality shown by the 

 venation of these three genera. The fact that in the typical and 

 most extensive genus in this subfamily (though in itself com- 

 paratively limited in number of species) the vein present is. 

 obviously the 7th and not the 6th justifies the assumption, in the 

 absence of stronger evidence to the contrary, that the vein present 

 in the abnormal genera is the 7th also. 



The principal genus Ptychoptera is further distinguished from 

 practically the whole of the rest of the Tipulidte by having the 

 3rd longitudinal vein forked, and this feature, in conjunction with 

 the presence of only one vein behind the 5th, renders the genus- 

 easy of recognition. The auxiliary vein in Ptyclioptera ends in 

 the costa, with no subcostal cross-vein uniting the auxiliary vein 

 with the 1st longitudinal. J 



* I am convinced by its general position and especially by its habit of 

 turning in suddenly to the wing-margin, that the vein that is present is the 

 7th and not the 6th, being in this view supported by Osten Sacken and by 

 Schiner (Fauna Austr. ii, p. 495), who both leaned to the same opinion; 

 Williston, usually so correct in the terminology of the venation, being I think 

 incorrect in considering it the 6th. It is therefore the 6th vein which is- 

 absent in this subfamily ; the 5th is obviously present in its usual place, 

 connected with the 4th by the posterior cross- vein. 



t It has been necessary in explaining the above point of view, to mention 

 genera not known from the Orient, but at least one species of Tanyderus is 

 Oriental. 



\ In some genera, however, the subcostal cross-vein is present, as, for 

 instance, in Protoplasia, Idioplasta and Tanyderus, its position in these being 

 similar to that in the LimnobhnvE. These genera are not Indian, but Tany- 

 derm occurs in Amboina. 



